Ametys 4.8 allows you to change your password, by setting the "Forgot password link" checkbox at population level.
A link to change the password is then displayed on the login forms:
This configuration is automatically activated on the 'System administrator' population.
If the password does not match the security rules, the system will force you to change the password (until it has been changed, it will not be possible to log in), except in safe mode and maintenance mode.